Ocean current measurement plays an important role in marine science research and engineering applications. Therefore, the research on new ocean current sensing technologies has always been a focus of marine scientific technological workers and marine engineering implementers. Marine organisms, especially fish, have a unique and highly sensitive sensory organ, that is, a lateral line system. Fish can effectively perceive a surrounding ocean flow field by using the lateral line system.
Ocean current sensors may be divided into a mechanical propeller type sensor, an electromagnetic sensor, an acoustic sensor, and an optical sensor according to a principle. Typical measuring instruments include an Ekman current meter, an S4 electromagnetic current meter produced by Interocean Inc. in the United States, a 2-D time difference type acoustic current meter produced by Falmouth Scientific Inc., an Aanderaa current meter RCM-9 (a Doppler acoustic current meter) in Norwegian, an acoustic Doppler current profiler, a particle imaging velocimeter PIV, and the like. These measuring methods have their own advantages, and also have specific disadvantages. For example, an acoustic sensor is affected by seawater temperature, salinity, suspended particles, acoustic scattering, multipath propagation, and the like, causing a decrease in precision; precision of an optical sensor is affected by seawater turbidity. In addition, the foregoing sensors cannot form a distributed sensor array.
Currently, most of signal sensing structures of existing bionic lateral-line sensors include three parts: a cilia stressed rod, a strain beam, and a deformation measurement unit, where the deformation measurement unit generally uses a strain gauge. Strain gauges are installed on plane parts of four strut beams of the strain beam respectively. As a result, a structure is complex, and it is not easy to install.